diff options
| author | Pauli <paul.dale@oracle.com> | 2018-10-26 10:54:58 +1000 |
|---|---|---|
| committer | Pauli <paul.dale@oracle.com> | 2018-10-29 07:47:22 +1000 |
| commit | 99540ec79491f59ed8b46b4edf130e17dc907f52 (patch) | |
| tree | abe34d519799a211c9135a3a882f7ba849774f0d /crypto | |
| parent | a9cfb8c2aa7254a4aa6a1716909e3f8cb78049b6 (diff) | |
Timing vulnerability in ECDSA signature generation (CVE-2018-0735)
Preallocate an extra limb for some of the big numbers to avoid a reallocation
that can potentially provide a side channel.
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/7486)
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/ec/ec_mult.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/crypto/ec/ec_mult.c b/crypto/ec/ec_mult.c index 7e1b3650e7..0e0a5e1394 100644 --- a/crypto/ec/ec_mult.c +++ b/crypto/ec/ec_mult.c @@ -206,8 +206,8 @@ int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r, */ cardinality_bits = BN_num_bits(cardinality); group_top = bn_get_top(cardinality); - if ((bn_wexpand(k, group_top + 1) == NULL) - || (bn_wexpand(lambda, group_top + 1) == NULL)) { + if ((bn_wexpand(k, group_top + 2) == NULL) + || (bn_wexpand(lambda, group_top + 2) == NULL)) { ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB); goto err; } @@ -244,7 +244,7 @@ int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r, * k := scalar + 2*cardinality */ kbit = BN_is_bit_set(lambda, cardinality_bits); - BN_consttime_swap(kbit, k, lambda, group_top + 1); + BN_consttime_swap(kbit, k, lambda, group_top + 2); group_top = bn_get_top(group->field); if ((bn_wexpand(s->X, group_top) == NULL) |